Thread-controlling mechanism for sewing-machines



.l. M'. MERROW. THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED APR. I. l9I5-. RENEWED SEPT. 12. I919.

1 319 886. E Patented Oct. 28,1919.

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HI: ATTORNEYS.

UNITED STATES PATENT OFFICE.

JOSEPH M. MERROW, OF HARTFORD, CONNECTICUT, ASSIG-NOR TO THE MERROW MACHINE COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

THREAD-CONTROLLING MECHANISM FOR SEWING-MACHINES.

Application filed April 1, 1915, Serial ITO/18,571.

State of Connecticut, have invented certain new and useful Improvements in Thread- Controllmg Mechanism for SeWmg-Machines, of which the following is a descriptio-n, reference being had to the accompanying drawings, and to the reference-figures marked thereon.

This invention relates to thread controlling mechanism for sewing machines. In the formation of stitches the instrumentalities employed usually operate in a manner which alternately tends to tension and slacken the thread carried or engaged thereby. The slack in a thread permits of itsbeing freely placed in position in the formation of a stitch, while the tension applied thereto serves to take-up released thread, to set the stitch and also to draw, for each stitch from the source of supply an amount of thread equal to that entering into the structure of a finished, stitch.

This treatment of the thread involves the actions, commonly designated in this art as a pulling-ofi action and a take-up action, and the amount of thread affected by each action may be referred to respectively as the pull-off and take-up. Slack thread as hereinafter referred to, will indicate any of the amounts of thread which may be released by the controlling mechanism, and such amounts may include; both pull-off and take-up.

During a period of operations comprising; one stitch forming cycle of the stitch forming instrumentalities, varying amounts of slack thread may be desirable. Provision of simple thread controlling mechanism whereby this result may be effectivelyaccomplished is the object of the present invention the various features of novelty of which are particularly set forth in the claims annexed to and forming a part of this specification. For a better understanding of the invention and of the advantages to be derived therefrom reference may be had to the accompanying drawings and descriptive matter wherein is illustrated and described one of the forms in which my invention. may be embodied.

Specification of Letters Patent.

Patented Oct. 28, 1919.

Renewed September 12, 1919. I Serial No. 323,437.

Referring to the drawings, Flgure 1 is a front elevation of an overseamlng machine provided with thread controlling mechanism embodying the present I invention, certain parts being broken away and others in section to more clearly illustrate cooperating parts.

Fig. 2 is a sectional view on lineQ-EZ of Fig. 1.

Fig. 3 is an enlarged sectional diagrammatic view on line 8-3 of Fig. 2 and,

Figs. 4 and 5 are'views similar to Fig.3 showing different positions of a thread engaging element. v

Like characters designate similar parts throughout the several views.

The Merrow type of machine shown in the drawings, being well known, may be described quite briefly with respect to its usual features of construction, wherein the stitch forming instrumentalities include the oscillatory eye pointed needle 3, upper'looper 4, lower looper 5, and chaining finger 6; The needle plate, work plate, feed dogs and presser-foot are designated by 7 8, 9 and 10 respectively. 1

The lower looper 5 is carried by a'slide 11 mounted for reciprocation on the frame cap 12 which is secured ,to the machine frame 13. Pivotally mounted on slide 11 is a carrier 14 for the'looper 4. Said carrier is 19 and 20 connected by intermeshing gears 21 and 22 so that when the shaft 17 is rotated by means of the pulley 23 the cams will rotate in unison. Cam cylinder 19 is provided with a. groove 24; cam cylinder 20 with a similar groove 25, said grooves bein adapted to receive respectively anti- 'IEIlClZlOll rolls 26 and 27 supported on studs 28 and 29 extending from the respective arms 15 and 16 of the looper carrier 14. Oscillatory movement is imparted to the needle 3 and its carrier 30 through the link 31 which connects said needle carrier with the eccentric extension 32 of shaft 18. Due; to the operative relation of the various parts ust described,rotation of shaft17 will efi'ect'an oscillatory movement of needle 3, an oscillooper 4, and a reciprocatory movement of lower looper 5. These movements are properly timed for cooperation of the several elements in the formation of stitches in a manner that is well understood by those familiar with the sewing machine art. Attention is however, directed to the fact that during one reciprocation or oscillation of the needle both loopers make two reciprocations laterally with respect to the path of the needle, the upper looper cooperating with the needle above the needle plate, the lower looper cooperating with the needle below the needle plate, and the loo-pers cooperating with each other below the plane of the needle plate and at one side thereof.

The oscillatory movement of the upper looper corresponds with the movement of the needle, that 'is,as the needle advances and passes below the needle plate said upper looper is moved around the edge of and below the needle plate, while when the needle recedes to its uppermost position above the needle plate, said upper looper is moved around the edge of and above the needle plate. During one of two similar lateral movements of the lower looper, executed in the formation of a stitch, the upper looper engages a loop of the thread carried by the lower looper and carries it above the needle plate to receive a loop of needle thread. The slack required in the lower looper thread to permit of this action is considerably in eX- cess of that which is required by said lower looper in making the other of the two lateral movements mentioned. Thread controlling mechanism to fulfil the different requirements of the conditions just set forth will now be described.

Such mechanism is shown associated with the thread primarily affected by the lower looper. It will be understood however, that thread primarily affected by other instrumentalities might be controlled by said mechanism with equal advantage. The thread 34 for lower looper 5 leads from a suitable supply (not shown) to the guide eye 35, passing therefrom to the tension 36, thread retaining and guiding eyes of the controlling device proper, (indicated in a general way by 37), guide 38 and finally through the eye of looper 5. The controlling mechanism includes in its make up a lever 40 consisting of an arm 41, removably supported on a carrier 42 which is pivoted on the stud 43 within the machine frame. The carrier 42 is of yoke form and it engages a block 44 fitted to the eccentric portion 45 of shaft 17 so that when the latter is rotated the lever will oscillate.

The arm 41 forming the free end of lever 40 projects through an opening in the machine frame. The outer end of said arm 41 is bent upon itself to form in efiect separated branches, there being two, as shown,

designated by 46 and 47. These branches are each provided with a thread engaging por tion both of which, are, during one posltion of lever 40, practically in a-linement with stationary thread guides 48 and 49 secured to the machine frame (see Fig. 4). A third stationary thread guide 50 also secured to the machine frame may be alined with the other two, or, for the purpose of varying a result as; will hereinafter appear, more or less removed from such alinement.

Oscillation of lever 40 causes the branches 46 and 47 to move correspondingly back and forth, the path of branch 46 being between guides 48 and 49 while the path of branch 47 is between guides 49 and 50. It will be observed that the thread 34 passes through an eye in the branch 46 and that the branch 47 is adapted to simply engage the thread on one slde. By virtue of this fact it is obvious and clearly illustrated in F 3, 4 and 5 that the branches act upon the thread through portions of their respective paths which differ in extent. The amount of this difference of effective movement may be changed to meet difierent requirements, pertaining to the take-up and pull-off, during a cycle of the stitch forming instrumentalities. For example in the particular arrange ment of the thread guides and engaging devices shown, it will be seen that a stroke of the lever 40 carrying the branches 46 and 47 to one side of the contiguous guides (as in Fig. 3) will ,pull-ofi' or take-up approximately one half the amount of thread that will be pulled off or taken up on the stroke of lever 40 which carries said branches to the opposite side of said guides (see Fig. 5). This proportion of pull-off or take-up is. efiected when the respective thread engaging portions of the branches 46 and 47 are alined in parallelism with the alinement of the eyes in thread guides 48 and 49. Changing the relation of said alinement will correspondingly change the result of the action upon the thread. The result may also be changed by changing the position of thread guide 50. These adjustments however, as well as others are quite obvious and it is believed need not be further considered herein, the broad invention residing as already intimated in the relation between elements of a single moving part and fixed thread guides whereby different amounts of pull-ofi and take-up are effected at intervals during a single stitch forming cycle of the stitch forming instrumentalities.

Having thus described my invention what I claim is,

1. A thread controlling mechanism for sewing machines, embodying in combination the following instrumentalities, to-wit: a plurality of thread engaging elements including pairs of elements with their thread engaging portions arranged in alternation,

one of the elements of one pair embodying means cooperating with the thread to deflect it in one direction only and the other elements embodying means for deflecting the thread in opposite directions, and means I the following lnstrumentalities, to-wit, a

plurality of thread engaging elements including pairs of elements with their thread engaging portions arranged in alternation, one of the elements of one pair having a thread engaging surface for deflecting the thread in one direction only and the other elements having opposed thread engaging surfaces for deflecting the thread in different directions, and means for moving alternate thread engaging portions transversely and to opposed sides of the thread path defined by the others, whereby different amounts of thread will be deflected on opposite sides of said path. j p

3. A sewing machine including in combination, a reciprocatory needle, a needle plate, a looper adapted to make two reciprocations below said needle plate to each reciprocation of the needle, a second looper movable from a plane above to a plane below the needle plate, said second looper being adapted to cooperate respectively with the needle and with the other loo-per upon alternate reciprocations of the latter, and means whereby a thread carried by the first mentioned loo-per may be controlled in a different degree during successive reciprocations of said first mentioned looper.

4:. A sewing machine including in combination, a reciprocatory needle, a needle plate, a looper adapted to make two reciprocations below said needle plate to each reciprocation of the needle, a second loo-per movable from a plane above to a plane below the needle plate, said second looper being adapted to cooperate respectively with the needle and with the other looper upon alternate reciprocations of the latter, a plurality of thread engaging elements, alternates thereof being movable to opposite sides of a general alinement of the others in synchronism with reciprocations of the needle, one of said elements being adapted to engage but one side of a thread engageable by the others on opposed sides, whereby the thread will be deflected at a greater number of points when the needle moves in one direction than when said needle moves in the opposite direction.

5. A sewing machine including in combination, a reciprocastory needle, a reciprocatory arm movable in synchronism with said needle and having separated portions adapted respectively to engage a thread on one side and on opposed sides, and thread guides substantially alined, interposed between the extreme positions into which the thread engaging portionsof the said reciprocatory arm are movable and separated to form spaces intersected by the respective paths of the said thread engaging portions of the reciprocating arm, whereby movement of said arms to one side of'the thread guides will deflect -a greater amount of thread than movement of said arms to'the other side of the thread guides.

6'. Thread controlling mechanism including in combination three thread guides, a

thread engaging element having separated portion-s extending into respective spaces between the thread guides, said portions being adapted respectively to engage a thread on one side and on opposed sides, and means for actuating the thread engaging element to move the separated portions simultaneously in the same direction across a path defined by the thread guides,

whereby different amounts of thread will be deflected on oppositesides of said path;

7'. Thread controlling mechanism including in combination, a bifurcated reciprocatory arm and three thread guides arranged to guide a thread in a general direction transverse to and intersected by the paths traversed by the branches of said bifurcated arm, one of said branches being effective to deflect the thread from one side of a path. defined by the thread guides and both of the branches being simultaneously eflective to deflect the thread from substantially the other side of said path, whereby reciprocation of the arm causes alternate deflection of different amounts of thread;

8. Ihread controlling mechanism including at least three separated thread guides and means operable th'erebetween comprising a plurality of thread engaging elements whereby upon movement of said means in any transverse direction the thread carried by said guide is bent and whereby when said means is moved a suitable distance in a certain direction an additional bend is produced in the thread, said thread engaging elements being adapted to simultaneously occupy positions on either of substantially opposite sides of a path defined by the thread guides, and means for reciprocating the thread engaging elements across said path, whereby different amounts of thread are alternately deflected.

9. Thread controlling mechanism including in combination, a plurality of thread engaging elements, alternates thereof being substantially alined, and means for eflecting relative movement of the alined elements collectively in the same direction across a thread path defined by the others, one of the elements being adapted to engage but one side of the thread which is engageable by the other elements on substantially opposite sides, whereby said relative movement alternately deflects different amounts of thread.

10. Thread controlling mechanism including in combination, a plurality of thread engaging elements, certain of which are movable in respective paths which extend through spaces defined by the others, and means for moving the movable elements collectively in the same direction across a thread path defined by the others, one of th elements being adapted to engage one side only of the thread which is engageable by the other elements on substantially opposite sides thereof, whereby different amounts of thread may be deflected from substantially opposite sides of said path.

11. Thread controlling mechanism includ ing in combination, a plurality of thread engaging elements, and means for moving alternates thereof collectively in the same direction across a thread path defined by the others, certain of the elements embodying means for engaging the thread on one side only while others embody means for engaging the thread on substantially opposite sides, whereby different amounts of thread may be deflected from substantially opposite sides of said path.

12. Thread controlling mechanism including in combination, areciprocatory arm having separated portions adapted respectively t engage a thread on one side and on opposed sides, and thread guides substantially alined, interposed between the extreme positions into which the thread engaging portions of the reciprocatory arm are movable and separated to form spaces intersected by the respective paths of the thread engaging portions of the reciprocating arm, whereby different amounts of thread may be deflected from substantially opposite sides of a path defined by the thread guides.

JosEPH M. MERROW.

Witnesses:

F. W. SPELLMAN, R E. ANDERSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, We.shington D. G. 

